Masters Theses

Date of Award

12-1984

Degree Type

Thesis

Degree Name

Master of Science

Major

Zoology

Major Professor

Mary Ann Handel

Committee Members

Joseph Daniel, John Kennedy, Alex Shivers

Abstract

The ability of abnormal sperm to bind to the zona peilucida was examined using techniques of fertilization in vitro. Sperm from the inseminates were grouped into classes according to their morphology. After fertilization in vitro cumulus-free ova were scored by phase contrast microscopy for the number and type of sperm bound to the zona. In some cases ova were also scored by scanning electron microscopy.

The percentages of abnormal sperm bound to the zona pellucida were shown to be significantly lower than the percentages of abnormal sperm in the inseminates. In addition, the percentages of abnormal sperm bound to the ova did not increase significantly over time. When the classes of abnormal sperm in the inseminates bound to the ova and were compared, it was found that Type 3 abnormal sperm were represented in the same frequency on the zona as in the inseminate; all other abnormal classes showed a binding frequency significantly lower than their frequency in the inseminate.

The scanning electron microscopy studies demonstrated that bound sperm associate in different ways with the zona pellucida. The majority of normal sperm were bound in a plane perpendicular to the zona, had vesiculated acrosomal membranes, and were secured to the ova by strands emanating from the zona. Type 2 and Type 3 abnormal sperm bound in a plane perpendicular to the ova, exhibited vesiculated acrosomal membranes and adhered tightly to the zona, while Type 5 and Type 6 sperm were bound to the ova in a plane parallel to the zona and were loosely attached.

It was concluded from these data that while abnormal sperm are able to participate in fertilization in vitro, they are less efficient than normal ill sperm. Furthermore, abnormal sperm seem to be able to undergo the process to capocitation at or near the rate of normal sperm or possibly do not require capacitation at all. Type 3 sperm seem to be exceptionally well adapted to binding to the zona pellucida and beginning the process of penetration.

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